This invention relates to vertically extendible platforms mounted on vehicles, such as an aerial ladder mounted on a fire truck. More particularly, the invention relates to an arrangement for preserving safety in the operation of an aerial ladder or the like while permitting its use in previously inaccessible areas.
Many safety and maintenance vehicles are equipped with vertically extendible devices to permit operation high above the ground. An example is an aerial ladder carried by a fire truck. These vertically extendible devices must be carefully supported and stabilized for the safety of persons using them. An aerial ladder on a fire truck, for example, is typically mounted on a rotatable base or platform which permits the ladder to be positioned at any point on a circular arc. The fire truck and ladder are stabilized by outriggers deployed outwardly on opposite sides of the truck. Such outriggers usually extend about five feet on each side of the fire truck and provide very good stabilization for any rotational position of the aerial ladder.
A disadvantage in the use of such outriggers, however, is the width or area they require when deployed. Narrow streets and alleys in many communities can inhibit the use of the longer aerial ladders because of the width required to deploy the supporting outriggers. Even in wider streets, the area required for the outriggers reduces flexibility in the choice of positions for the fire truck. Despite the disadvantage in their use, outriggers are required for safe operation on the extended aerial ladders.